Arrangement for avoiding double pulloffs in systems serving singling-out of flat articles



y 3, 1965 F. BUCHWALD 3,194,552

ARRANGEMENT FOR AVOIDING DOUBLE PULL-OFFS I IN SYSTEMS SERVINGSINGLING-QUT OF FLAT ARTICLES Filed May 1, 1962 2 Sheets-Sheet 1INVENTOR FRITZ BUCHWALD ATTORNEY July 13, 1965 Filed May 1, 1962 F.BUCHWALD ARRANGEMENT FOR AVOIDING DOUBLE PULL-OFFS IN SYSTEMS SERVINGSINGLING-OUT OF FLAT ARTICLES 2 Sheets-Sheet 2 Fig. 2

INVENTOR FR/TZ BUC/vM/ALD ATTORNEY United States Patent 3,194,552ARRANGEMENT FOR AVOIDING DQUBLE PULL- OFFS 1N SYSTEMS SERVINGSINGLlNG-OUT 0F FLAT ARTICLES Fritz Buchwald, Thaliaweg, Germany,assignor to International Standard Electric Corporation, New York, N.Y.,a corporation of Delaware Filed May 1, 1962, Ser. No. 191,593 Claimspriority, application Germany, May 2, 1961, St 17,768 7 Claims. (Cl.271-26) This invention relates to document sorting systems and moreparticularly to an arrangement for avoiding double pull-offs in systemsrequiring the singling-out of flat articles.

The singling-out of piled articles plays an important role inmechanizing and automatizing the handling of documents. Especially withrespect to the feeding-in of thin documents, such as checks or bills toaccounting machines, special care has to be taken that the documents areindividually fed to a conveying system with a constant minimum spacing,before being fed to the processing positions or machines. If, due to adouble pull-off, two documents are conveyed simultaneously, itis likelythey will be recognized by the processing machine as one singledocument, so that one of these documents will be completely skipped inprocessing. Such an error, if detected, would call for a checking of allof the already processed documents, thus making it very doubtful whetherthe whole system is economical. For this reason arrangements have to beprovided for reliably preventing such a double or multiple pull-olf. Inaddition thereto it is still required that such an arrangement must notonly be capable of operating with a high accuracy, but also at a highspeed. Thus, for example, 30 and more documents must be capable of beingsingled out per second with a practically constant spacing between them,without causing a double or multiple pull-off.

Since also documents of a thin material, such as of a low-resistancepaper, have to be processed, a careful handling of the documents must besafeguarded by the singling-out arrangement.

With respect to the above mentioned machines it is a further requirementthat the supply of the documents must be capable of being randomlyinterrupted, and continued thereafter.

It is the object of the present invention to provide an arrangementmeeting the above mentioned requirements. One of the features of thisinvention is the use of opposing forces of suction of unequal force toeffect a separation of piled up articles.

This invention relates to an arrangement adapted to reliably avoid adouble or multiple pull-off in a preferably pneumatic type of systemserving the separation (pullolf) of piled flat and thin articles such asdocuments made of thin paper, wherein the pulled-off articles areconveyed by an apertured belt which is led over the openings of a sourceof suction air. The invention consists in that in the conveyingdirection, beyond the pull-oil? device, and at the two opposite sides ofthe conveying channel, there are arranged the outlets of a source ofsuction air, of which those on the side of the perforated conveyor beltare provided with the larger suction holes, and thus have the greatersuction force, while those on the opposite side are arranged in theconveying direction in front of the first mentioned openings, and arethus spaced apart the conveyor belt by a distance corresponding to somethicknesses of the material of the articles to be conveyed. This spacingis in the order of about one or more millimeters. The sucking-offairducts of both groups of outlets are assembled in one common pipe andare throttled sharply Patented July 13, 1965 ice in such a way that anundcrpressure can only build itself up with the pipe system when thelarge-diameter outlets on the side of the conveyor belt are throttled bythe articles to be conveyed.

The invention will now be explained with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of an arrangement in accordance with myinvention;

FIG. 2 is a schematic view of the arrangement shown in FIGURE 1.

The piled articles to be singled-out or separated, i.e. a

pile of equisized checks or other documents, are contained in areceiving device 1. With a constant pressure this pile of articles ispressed by the action of a not shown device, against the conveyingplane, so that the front article will come to lie against the belt 6.This conveyor belt 6, in turn, is led over a surface on which there arearranged the outlets 2 and 3 of a source of suction air. Suction iselfected at 2 and 3 via tubes 2a and 3a. Valve V controls the suction tooutlets 3. The outlets 3 are arranged in the central portion of thesurface, and have a high suction force. The outlets 2 have a smallersuction force, and are arranged at the margins of the surface. The belt6 is provided with perforations 6a, being in agreement with the outlets3, for performing the suckingon of one of the documents and for takingit along.

The belt 6 covers only the central portion of the surface occupied bythe outlets 3, so that the outlets 2 remain uncovered. The side of thereceiving device 1 lying in the conveying direction, may be formedeither by a limit stop, a roller, or a retaining device 5 extending sofar to the conveyor belt, that there will only remain a small gap forpulling off the conveyed articles. Reference numeral 4 indicates theblowing nozzles, the purpose of which will be explained hereinafter inconnection with describing the mode of operation of the system. a

To the short pipe pieces 2a and 3a there are connected the sources ofsuction air, and to the short pipe piece 4a which supplies 4 with airthere is connected a source of compressed air. Along the conveying path,and behind the pull-off device, there is provided an arrangement 7 inaccordance with my invention for avoiding a double or multiple pull-off.This arrangement 7 likewise consists of a surface over which theperforated conveyor belt is led, which is provided with suction-airnozzles, and furthermore of another arrangement of suction-air nozzleswhich, together with the aforementioned surface, forms the secondopposite side of a conveying channel, and likewise contains suction-airnozzles. In the common airduct of both nozzles there is arranged athrottle valve B which is shown in FIG. 2.

In order to ensure a minimum spacing between the individual separatedarticles, the singling-out device is operated by the article to beconveyed with the aid of photocells. Thus, for example, there may beprovided four light barriers 1t), 11, 12 and 13, of which the sources oflight are arranged on the one side, and the receivers on the other sideof the conveying channel. Further suctionair nozzles 8 and 9 aredisposed behind the arrangement 7 on a surface, over which the conveyorbelt 6 is moved. When a document has passed through 7 the valve V isclosed causing suction to go through tubes 8a and 9a to outlets 8 and 9for conveying the document further along the system. For the purpose ofimproving the pull-off operation, it is known to bend the first objectof a pile, for increasing the rigidity of the article, and making itmore suitable for being transported. For this reason the surface isappropriately bent in such a way that upon sucking-on of the firstarticle to be conveyed, this article will likewise be bent. This iseffected by the suction-air nozzles 2 with the assistance of theblowing-air nozzles 4.

ing between the light barriers 10 and 11. thereto the light barriers 11,12, and 111, 13 may also be used to perform a spaceand length-control inthis man- The conveyor belt is of a width which does not cover- .up thesuction-air nozzles 2 or 3 respectively, and therefore need only be bentslightly or not at all. In order that the article to be, conveyed isretained close'to the belt 6, and is conveyed in opposition to theholding effect of the nozzles 2, the suction effect of the nozzles 3must be substantially stronger than that of the nozzles 2. Bebind thepull-E device the bending of the articles to be conveyed is maintainedwith the aid of guides (not shown). The nozzles 8, on one hand, and 3,'7, 9, on the other hand, are alternately applied to a source of suctionair via a quick-acting valve V By reversing this valve the system may berandomly switched to cause either the transporting or the stopping.

The arrangement shown in the drawings operates as follows: First of allthe receiving device 1 is provided with a pile of aligned documentsresting on one hand, on the base plate of the supporting device and, onthe other hand, against the limit stop or retaining plate 5. The frontpiece of the piling device (stacking device) is applied with its centralportion to the bolt 6 moving in the conveying direction, whereas its twomarginal-strip portions are loosened by. the action of the blowing-airnozzles 4, and sucked-on by the stationary nozzles 2, thus being bentabout an axis extending in the conveying direction. then a vacuum isapplied to the nozzles 3, so that the When an article is supposed to beconveyed article is sucked so strongly against the belt 6 that it, in

opposition to the retaining force of the fixed nozzles 2, is taken alongby the belt until its front end, between the opposite walls of thedevice '7, will darken the light barrier 10. On account of this valve Vwill disconnect the vacuum from the nozzles 3, so that a conveyance isno longer performed from this end. After having passed the conveyingnozzles F of the device 7 a strong vacuum is permitted to be built up inthe strongly throttled boxes 7a which are connected to the air supply,thus performing the further conveyance of the article. At the same timethis vacuum appears on the opposite side of the article to be conveyed,namely at the retaining nozzles H, so that the article will be retained.The relationship between the nozzles F and H is such that the conveyanceis continued in opposition to the retaining force of H. However, iftogether with the first article to be conveyed, a second one has beentaken along accidentally as well, then this second article will beretained by the holding nozzles until either the passing article to beconveyed has released the light barrier 14 or until the subsequentlyarranged light barriers perform the call-up of further articles.

In the course of the further conveying process first of all the lightbarrier 11 and thereupon the light barrier 12 is darkened. The lightbarrier 12 is arranged at a point where the conveying article is takenover by a further group of suction-air nozzles 9. Here the articleitself shuts off the nozzles of the device 7 for interrupting the supplyint his way. After the rear edge of the article to be conveyed haspassed the light barrier 11, the device 7 is switched-on to becomeeffective again. In this way, between the individual articles to beconveyed, there is established a spacing corresponding to the spac- Inaddition ner.

If, for some reason or other, the conveying operation is supposed to bestopped, then the vacuum is switchedoif from the conveying nozzles 3, 7and 9 by the main valve V and is applied to the retaining nozzles 3. Inthis way it is possible to perform a random stopping vand re-starting ofthe conveying operation.

While I have described the principles of my invention in connection withspecific apparatus, it is to be clearly understood that this descriptionismade only by way of example and not as a limitation to the scope of myinvention as set forth in the accompanying claims.

r 4 What is claimed is: p 1.,Arrangement for singling out and conveyingflat, thin articles, from a stack of such articles comprising:

a perforated belt; guide means for causing said belt to follow minedpath in an edgewise position;

means for holding a stack of such articles adjacent said path;compressed air means having outlets adjacent said's'tacl; and directedthereto to separate a foremost article, in said stack of said articles,from said stack; first suction means adjacent said belt on the sideopposite said stack with a given'suction power which cooperate with saidbelt to convey said articles; second suction means, with less suctionpower than said given power, disposed on the other side of said stackopposite said first suction means .to draw and hold thereto any adjacentarticle overlapping and conveyed with said foremost article; and controlmeans, including sensing means positioned along said path to controlsaid first suction means and space said articles, to cooperate with saidbelt and said first suction means to subsequently convey said anyadjacent article, and to start and stop operation of said arrangement.2. Arrangement for singling out and conveying flat, thin articles from astacl; of such articles comprising:

a perforated belt; guide means to direct said belt along a predeterminedpath in an edgewise position; means for holding a stack of such articlesadjacent said path; compressed air means having outlets adjacent saidstack and directed thereto to separate a foremost article, in said stackof said articles, from said stack; first suction means adjacent saidbelt on the side opposite said stack with a set suction power whichcoopcrates with said belt to convey said articles; second suction means,with less suction power than said set suction power, disposed along saidpath adjacent said stack to bend said foremost article away from saidstack; third suction means, with less suction power than said setsuction power, disposed on the other side of said stack. opposite saidfirst suction means, to draw and hold thereto any adjacent articleoverlapping and conveyed with said foremost article; and control means,including sensing means positioned along said path to control said firstsuction means and space said articles, to cooperate with said belt andsaid first suction means to subsequently convey said any adjacentarticle, and to start and sto operation of said arrangement. 3.Arrangement for singling out and conveying flat, thin articles,comprising:

compressed air means having at least one output directed towards saidarticles-to separate a foremost article to be conveyed; conveying meansadjacent said articles, including -a perforated belt, and first suctionmeans behind said belt with a given suction power for pulling thearticles to the a predeterbelt bending means, including second suctionmeans adjacent said foremost article and said belt with less suctionpower than said given suction power, and 1 guiding means adjacent saidforemost article, wherein both said suction means cooperate to bend saidarticle away from any adjacent article overlapping therewith;holdingmeans, including third suction means positioned along said belton the side opposite said first suction means with less suction powerthan said given suction power to hold said any adjacent article torevent overlapping conveyance thereof with said foremost article; and Vv control means, including sensing means positioned along said path tocontrol said first suction means and space said articles, to cooperatewith said conveying means to subsequently convey said any adjacentarticle, and to start and stop operation of said arrangement.

4. Arrangement for singling out and conveying flat,

thin articles, comprising:

a perforated belt;

guide means for causing said belt to follow a predetermined path in anedgewise position;

a plurality of compressed air outlets arrayed along and directed acrosssaid path to separate a foremost article in a stack of said articlesfrom said stack;

a first plurality of suction outlets arrayed in the center of said path,over which said belt passes;

a second plurality of suction outlets arrayed along said epath,interposed between said plurality of compressed air outlets and saidfirst plurality of suction outlets;

a third plurality of suction outlets arrayed in the center of said path,disposed a distance along said path from said first plurality;

a fourth plurality of suction outlets arrayed in a plane opposite tosaid third plurality, wherein said belt passes therebetween;

a fifth plurality of suction outlets arrayed in the center of said path,disposed a distance along said path from said third plurality;

two lengthwise arrays of suction outlets, one above and one below saidfifth plurality, extending along said path;

said first, third, and fifth pluralities cooperating with said belt toconvey said foremost article along said path;

said second plurality causing said foremost article to be bent away fromsaid stack;

said fourth plurality causing any adjacent article, overlapping saidforemost article to adhere thereto; and

control means to space said articles, to cooperate with said belt andwith said third and fifth luralities to subsequently convey said anyadjacent article, to start and stop operation of said arrangement, andto cooperate with said lengthwise arrays wherein said arrays hold anyarticle thereat during halt.

5. Apparatus for singling out flat thin articles and conveying thearticles comprising: a perforated belt; guide means for causing saidbelt to follow a predetermined path in an edgewise position; a firstgroup of suction outlets on one side of said path which cooperate withsaid belt; a second group of suction outlets on the other side of saidpath disposed opposite to said first group, said second outlets beingsmaller than said first outlets; a common source of suction air for bothsets of outlets so that a single article will be drawn to said belt andconveyed by it and an adjacent article overlapping therewith will bedrawn to said second group of outlets and held by said second group;and, control means for causing said adjacent article to be conveyedalong said path by said belt a predetermined distance behind said singlearticle, said guide means comprising means for causing said belt to beguided over a surface which is concave in relation to said belt, theaxis of said concavity being parallel with said path.

6. Apparatus according to claim 5 wherein the concave surface on whichthe perforated conveyor belt is guided, is provided with suction-airoutlets in its central portion and in its marginal-strip portions.

7. Apparatus according to claim 6 wherein said perforated conveyor belttraverses the surface of said central portion, placing the perforationsin said belt in registry with said suction-air outlets of said centralportion, saidregistry thereby configuring a given suction-air area witha given suction force; and

said suction-air outlets in said marginal-strip portion form asuction-air area which is smaller than said given area, having lesssuction force than said given suction force.

References Cited by the Examiner UNITED STATES PATENTS 734,670 7/03Cleathero 271--56 2,063,479 r12/ 36 Belluche. 2,168,559 8/39 Cernak27'l56 2,822,170 2/58 Frantz 271-64 2,856,187 10/58 Burckhardt et a127147 X 2,905,309 9/59 Makrides l98--'3l.1 2,941,653 6/60 Kriemelmeyer198-31.1 2,941,654 6/60 Falconer 19834 3,086,770 4/63 Richert 27127ROBERT B. REEVES, Acting Primary Examiner.

ROBERT A. LEIGHEY, HADD S. LANE, Examiners.

1. ARRANGEMENT FOR SINGLING OUT AND CONVEYING FLAT, THIN ARTICLES, FROMA STACK OF SUCH ARTICLES COMPRISING: A PERFORATED BELT; GUIDE MEANS FORCAUSING SAID BELT TO FOLLOW A PREDETERMINED PATH IN AN EDGEWISEPOSITION; MEANS FOR HOLDING A STACK OF SUCH ARTICLES ADJACENT SAID PATH;COMPRESSED AIR MEANS HAVING OUTLETS ADJACENT SAID STACK AND DIRECTEDTHERETO TO SEPARATE A FOREMOST ARTICLE, IN SAID STACK OF SAID ARTICLES,FROM SAID STACK; FIRST SUCTION MEANS ADJACENT SAID BELT ON THE SIDEOPPOSITE SAID STACK WITH A GIVEN SUCTION POWER WHICH COOPERATE WITH SAIDBELT TO CONVEY SAID ARTICLES;